In many medical applications, it is necessary to connect one section of medical tubing, e.g., a catheter, with another. Generally speaking, it is important that these connections be relatively secure and stable so that the tubing does not separate or develop leaks at the connection point. Security and leak-resistance take on special importance in applications where the tubing sections are implanted in a human body.
One procedure that necessitates implantation of medical tubing into the body involves the use of an implantable drug infusion pump. Such pumps are often used to control pain and/or spasticity, as well as to provide one or more drugs or fluid medications to a particular location within the body. For instance, a typical implant procedure may involve implanting a drug infusion pump into a cavity or subcutaneous pocket in the body and delivering a drug, via a catheter(s), to an epidural space or intrathecal space of the spinal column or to a particular location within the brain. In this exemplary application, a catheter assembly having two or more catheter sections, e.g., a thin-walled distal section (near the implantation site) and a thicker-walled proximal section (connected to the infusion pump), may be used to deliver the drug to the desired site.
The distal catheter section may be positioned in the desired location in the body and then connected to the proximal catheter section by use of a medical tubing connector. The connection may be made by inserting one end or prong of the connector into a lumen at one end of one catheter section (e.g., the proximal section) and the other end of the connector into a lumen of one end of the other catheter section (e.g., the distal section) and then sliding both catheter sections towards one another (toward the middle of the connector). An opposite end of the proximal section may then be connected to the drug infusion pump. Sutures may be placed around the catheter/connector prong to secure the catheter to the connector as well as to attach the catheter/connector to tissue.
While adequate for their intended purpose, inherent variability in suturing techniques may result in a suture that is incorrectly placed relative to the catheter and connector. In this case, the suture may pinch-off or otherwise interrupt normal catheter flow. Moreover, even when correctly placed, a physician may cinch the suture too tightly or, alternatively, too loosely. As a result, the suture may occlude the catheter or, if the suture is too loose, permit it to separate from the connector.
Other potential problems with some existing catheter connectors include a lack of adequate strain relief to the connection. Without proper strain relief, connector ends may damage (e.g., tear through) the catheter during or after implantation.